ASP4058 is an orally active, next-generation sphingosine 1-phosphate (S1P) receptor agonist that shows selectivity for S1P1 and S1P5 over other S1P receptors in vitro [4]. Most likely used as the hydrochloride salt (PubChem CID 16755142). Compare this with the non-selective S1P agonist fingolimod, which was the first oral drug to be approved for relapsing forms of MS.Studies in animal models suggests that ASP4058 may also be beneficial in ameliorating the chronic arterial wall inflammation observed as underlying intracranial aneurysm (IA) [3].